The present invention relates to an apparatus for reading and writing information from/to a recording medium and, more particularly, to such apparatus for use with broadcasting stations for reading and writing information pertaining to a respective broadcasting station from/to a recording medium.
Broadcasting stations (or the like) broadcast signals, such as video and audio signals, which may be recorded on recording mediums, such as magnetic tapes having a width of 1/2 inch, 3/4 inch and so forth. These magnetic tapes are typically supplied from one broadcasting station to another. For example, magnetic tapes may be supplied between the broadcasting stations of the same broadcasting network, such as between a so-called key station and any of the local affiliated stations in the respective broadcasting network.
Each broadcasting station may assign identification (ID) information representative of the respective station to a tape. More specifically, such ID information may be coded and recorded in a time code track of the tape so as to enable the respective broadcasting station to be identified, as hereinafter more fully described. Such ID information may be formed of one or more symbols and/or numbers.
Further, each of the stations may also add control information to the tape which may be utilized for controlling the transmission of the contents of the tape by the respective station. Such control information may be recorded in the time code track of the tape in a manner similar to that of the ID information.
With regard to the time code, a time code may be produced by recording a tape address of a tape in a time unit form. Such time code may conform to a standard, such as a SMPTE (Society of Motion Picture and Television Engineers) standard (C98.12: time and control code for video and audio tape for a 525/30 television system), which may have 80 bits per frame. In the SMPTE time code, 32 bits per frame may be designated for use by a user. Both the ID information and the control information may be recorded within such user's bits.
As is to be appreciated, the identification (ID) information is preferably different for each respective station. Furthermore, the key station and affiliated station(s) may not always broadcast the same programs or may not broadcast a program in the same manner. For example, an affiliated station may decide to insert a different number of commercials and at different times than the key station. As such, the ID and control information and/or the recording positions thereof may be different for each broadcasting station.
When a tape is delivered from the key station to an affiliated station, the affiliated station may not be able to broadcast the program(s) recorded on this tape without changing the information added thereto by the key station. For example, if the affiliated station broadcasts the contents of the tape without changing the control information previously added by the key station, then a broadcasting error may occur wherein the tape is stopped at an incorrect position based on the control information added by the key station.
Therefore, the affiliated station should not use a tape received from the key station having ID and control information associated with the key station without assigning new ID and control information to such tape. In particular, the affiliated station should determine the recording positions for new ID and control information, erase the ID and control information recorded in the time code by the key station, and write new ID information and new control information in the time code track which pertains to the affiliated station.
To rewrite or overwrite such ID and control information, the affiliated station reproduces the recorded tape received from the key station at a normal playback speed by using a dedicated video tape recorder/reproducer (VTR) controller. During such reproduction, the affiliated station reads and decodes the coded ID information and control information recorded in the time code track, and superposes the decoded ID information and control information onto a picture and displays the same on a monitor to confirm the ID information and the control information. The affiliated station may then erase the ID and control information associated with the key station, and record ID and control information which pertains to the respective affiliated station.
Prior to returning the tape to the key station, the affiliated station erases the recorded ID and control information pertaining to the affiliated station, and records the original ID and control information associated with the key station.
The above-described operation is only performed while the tape is reproduced at normal playback speed. As a result, when a tape having a recording time of 60 minutes is supplied to an affiliated station from a key station, it takes 60 minutes to rewrite the ID and control information associated with the key station for the affiliated station and another 60 minutes to rewrite the ID and control information of the affiliated station for the key station for a total of approximately 120 minutes. As is to be appreciated, this procedure is inefficient.
If, however, the tape is reproduced at a speed higher than the normal playback speed, the above-described dedicated VTR controller may not properly reproduce or process the pictures and/or information obtained from the tape. During such improper video processing by the dedicated VTR controller, the ID and control information may not be properly displayed on the monitor which may prevent confirmation of the ID and control information.
Accordingly, it is desirable to detect ID and control information at a relatively high speed. Moreover, it may be desirable to perform the high-speed searching operation of the portion of the tape having the ID and control information recorded therein with reference to a STOP code (control information) located at the head of the portion which may be utilized for broadcasting the contents of the tape.
Further, although the above-described dedicated VTR controller may be utilized for confirming the ID and control information displayed on the monitor as previously described, such VTR controller may not be utilized for providing a copy or printout of the ID and control information superimposed on a picture. As is to be appreciated, a broadcasting station may desire to obtain a printout of such ID and control information.
Furthermore, a broadcasting station may not have an apparatus for erasing and recording ID information and/or control information. That is, editing of a tape is normally performed by an editing section which sends the edited tape to a broadcasting station. Accordingly, it may be desirable to provide an apparatus for erasing and recording ID information and/or control information which is relatively inexpensive and/or which is relatively easily adaptable to existing equipment at the broadcasting station.
Additionally, signals corresponding to a plurality of broadcasting stations may be recorded on one tape. In such situation, a user may perform operations involving the ID information (e.g., erasing ID information, recording ID information and so forth) based only on the user's memory. As such, it may be difficult for the user to correctly remember various ID information for different operation logs. Accordingly, it may be desirable to provide system wherein a user can reliably determine and retain the recorded ID and control information.
Further, if an operation log having reference to ID information can be discriminated, then a group of ID and control information referenced to operation logs may be collectively processed. For example, consider the situation in which ID and control information for the key station is not erased and ID and control information for an affiliated station is independently recorded on a tape. In this situation, the information for the key station and the information for the affiliated station may be processed independently upon detection.